Glasgow | 26-ITP-May | Christelle Boten | Sprint 1 | Coursework

Sprint-1/1-key-exercises/1-count.js

@@ -4,3 +4,4 @@ count = count + 1;
 
 // Line 1 is a variable declaration, creating the count variable with an initial value of 0
 // Describe what line 3 is doing, in particular focus on what = is doing
+// Here, line 3 is a statement that is reassigning a value to count by incrementing it by 1.

Sprint-1/1-key-exercises/2-initials.js

@@ -5,7 +5,8 @@ let lastName = "Johnson";
 // Declare a variable called initials that stores the first character of each string.
 // This should produce the string "CKJ", but you must not write the characters C, K, or J in the code of your solution.
 
-let initials = ``;
+let initials = firstName[0] + middleName[0] + lastName[0];
+console.log(initials);
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 

Sprint-1/1-key-exercises/3-paths.js

@@ -17,7 +17,7 @@ console.log(`The base part of ${filePath} is ${base}`);
 // Create a variable to store the dir part of the filePath variable
 // Create a variable to store the ext part of the variable
 
-const dir = ;
-const ext = ;
+const dir = filePath.slice(0, lastSlashIndex);
+const ext = base.slice(base.lastIndexOf("."));
 
 // https://www.google.com/search?q=slice+mdn

Sprint-1/1-key-exercises/4-random.js

@@ -7,3 +7,11 @@ const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 // Try breaking down the expression and using documentation to explain what it means
 // It will help to think about the order in which expressions are evaluated
 // Try logging the value of num and running the program several times to build an idea of what the program is doing
+
+console.log(num);
+
+// Here, Math.random creates a random decimal number greater than or equals to 0 and less than 1. It can be any decimal number in between.
+// The function Math.floor rounds down any decimal number to the nearest integer to give it a whole number.
+//In Javascript, the the expression in the bracket is read first. Here, we started by doing (maximum - minimum + 1) which is (100 - 1 + 1). The answer is 100.
+// The next evaluation is creating a random number by reading the function Math.random(0<= random number < 1), we will multiply it by the result of (100 - 1 + 1 which is 100), then round it down to the nearest integer
+// Then add all of that to 1 which is the minimum number.

Sprint-1/2-mandatory-errors/0.js

@@ -1,2 +1,4 @@
-This is just an instruction for the first activity - but it is just for human consumption
-We don't want the computer to run these 2 lines - how can we solve this problem?
+//This is just an instruction for the first activity - but it is just for human consumption
+//We don't want the computer to run these 2 lines - how can we solve this problem?
+
+//  We use two forward slashes to comment things we do not want the computer to read. It is for human reading only. 

Sprint-1/2-mandatory-errors/1.js

@@ -1,4 +1,6 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33;
 age = age + 1;
+
+// we can reassign values when using the "let" in declaring variables. 

Sprint-1/2-mandatory-errors/2.js

@@ -1,5 +1,9 @@
 // Currently trying to print the string "I was born in Bolton" but it isn't working...
 // what's the error ?
 
-console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);
+
+
+// the variable 'cityOfBirth' had to be declared first before doing the console log.
+// This is because the Javascript reads from top to bottom

Sprint-1/2-mandatory-errors/3.js

@@ -1,9 +1,15 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = String(cardNumber).slice(-4);
+
+console.log(last4Digits);
 
 // The last4Digits variable should store the last 4 digits of cardNumber
 // However, the code isn't working
 // Before running the code, make and explain a prediction about why the code won't work
 // Then run the code and see what error it gives.
 // Consider: Why does it give this error? Is this what I predicted? If not, what's different?
 // Then try updating the expression last4Digits is assigned to, in order to get the correct value
+
+//Prediction: The slice method doesn't work on numbers and integers. It only works on strings and arrays
+//Error message: The error message states that "Slice is not a function"
+//Change the numbers (integer) to String

Sprint-1/2-mandatory-errors/4.js

@@ -1,2 +1,5 @@
-const 12HourClockTime = "8:53pm";
-const 24hourClockTime = "20:53";
+const HourClockTime = "8:53pm";
+const hourClockTime = "20:53";
+
+console.log(HourClockTime, hourClockTime);
+// When declaring variables, we do not use numbers to name the variable. 

Sprint-1/3-mandatory-interpret/1-percentage-change.js

@@ -2,7 +2,7 @@ let carPrice = "10,000";
 let priceAfterOneYear = "8,543";
 
 carPrice = Number(carPrice.replaceAll(",", ""));
-priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," , ""));
 
 const priceDifference = carPrice - priceAfterOneYear;
 const percentageChange = (priceDifference / carPrice) * 100;
@@ -12,11 +12,21 @@ console.log(`The percentage change is ${percentageChange}`);
 // Read the code and then answer the questions below
 
 // a) How many function calls are there in this file? Write down all the lines where a function call is made
+//There are three function calls here. "replaceAll" which replaces every "," with an empty space, therefore removing the comma. 
+// We equally have console.log which prints out.
+//The last function is Number() which changes everything in it into a number/integer. Here, it changes String to numbers. 
 
 // b) Run the code and identify the line where the error is coming from - why is this error occurring? How can you fix this problem?
+//Line 5 was missing a separation comma.
 
 // c) Identify all the lines that are variable reassignment statements
+// Line 4 and Line 5 have variables being reassigned.
 
 // d) Identify all the lines that are variable declarations
+//Line 1, line 2, line 7 and line 8 have variable declarations
+// Here, we have declared variables by using let and const. We have variable called carPrice, priceAfterOneYear, priceDifference and percentageChange.
+// We have given values to these variables as well which can be seen after the equals sign.
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+//This expression removes the comma in the price from 10,000 to 10000
+//Here, every time the function reads a comma (","), it replaces the comma with "" which is basically an empty space. In other words, it removes the comma in a expression

Sprint-1/3-mandatory-interpret/2-time-format.js

@@ -1,4 +1,4 @@
-const movieLength = 8784; // length of movie in seconds
+const movieLength = 8784 // length of movie in seconds
 
 const remainingSeconds = movieLength % 60;
 const totalMinutes = (movieLength - remainingSeconds) / 60;
@@ -12,14 +12,23 @@ console.log(result);
 // For the piece of code above, read the code and then answer the following questions
 
 // a) How many variable declarations are there in this program?
+// There are 6 variable declarations
 
 // b) How many function calls are there?
+// There is one function call which is console.log
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+// % is a remainder operator which will do movieLength / 60. This will give us the remainder which we will consider the remainder of this operation
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// In line 4 we are declaring the totalMinutes. we have the remainingSeconds which is 24. Then we will do ((8784 - 24) /60) =  146
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// The variable result shows the total remaining duration of a movie in terms of hours, minutes and seconds. We can also call it remainingTime.
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// When using -8784, I had the same answers with 8784, except they were all negative numbers. -2:-26:-24
+// When using 87.84, I had 0:1:27.840000000000003 which is still a readable time. But it doesn't round up the decimal numbers. 
+// When using the String "8784", I had 2:26:24 which is the same answer as when I used 8784. Javascript is converts strings to integers automatically when subtracting
+// When using the string "hello", I get the outcome NaN:NaN:NaN which means "Not a Number". the string hello can't work in divisions. 

Sprint-1/3-mandatory-interpret/3-to-pounds.js

@@ -25,3 +25,9 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+// 2. const penceStringWithoutTrailingP = "399p".substring( 0,  penceString.length - 1): Here we use the subString method which will slide the string of 
+// penceString starting at index 0 and ending at index 2 (3 - 1). The result should be "399"
+// 3. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"): Here we want to make sure that the penceStringWithoutTrailingP variable has at least 3 characters, if that is not the case, we will add "0" infront of the character till it reaches the length required.
+// Here, paddedPenceNumberString = "399" . Then pounds =  "3"
+// 4. const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0") : The substring(paddedPenceNumberString.length - 2) will return 99  and the padEnd(2,"0") will make sure that there are at least two characters here.
+

Sprint-1/4-stretch-explore/chrome.md

@@ -11,8 +11,11 @@ In the Chrome console,
 invoke the function `alert` with an input string of `"Hello world!"`;
 
 What effect does calling the `alert` function have?
+Answer: It creates a pop up window on the browser.
 
 Now try invoking the function `prompt` with a string input of `"What is your name?"` - store the return value of your call to `prompt` in an variable called `myName`.
 
 What effect does calling the `prompt` function have?
+Answer: It creates a pop up window which allows the user to input data. This prompt has a cancel and an 'OK' button.
 What is the return value of `prompt`?
+Answer: The return value will depend on what the user inputs. If the user presses the 'cancel' button, then the return is null. If the user presses 'OK' without entering anything, then the return type is an empty string. Else if something is written by the user, then the return value will be what the user has entered.

Sprint-1/4-stretch-explore/objects.md

@@ -5,12 +5,20 @@ In this activity, we'll explore some additional concepts that you'll encounter i
 Open the Chrome devtools Console, type in `console.log` and then hit enter
 
 What output do you get?
+Answer: I get this ƒ log() { [native code] }
 
 Now enter just `console` in the Console, what output do you get back?
+Answer: {debug: ƒ, error: ƒ, info: ƒ, log: ƒ, warn: ƒ, …}
 
 Try also entering `typeof console`
+Answer: object
 
 Answer the following questions:
 
 What does `console` store?
+Answer: Console stores a lot of objects like assert, clear, error, info, warn, log, debug and more.
+
 What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+Answer: Console.log helps to print out a message.
+Console.assert writes an error message to the console if the assertion is false. If the assertion is true, nothing happens.
+`.` is used to access the properties or methods of an object